Method and apparatus for filling bulk material

ABSTRACT

A method and apparatus for filling bulk material, in which an objective filling weight for filling bulk material stored in a storage portion of a filling object is divided to a first stage objective filling weight and a second a second stage objective filling weight. The method consists of setting an opening/closing mechanism provided on the storage portion to a predetermined opening degree and filling the bulk material from the storage portion to the filling object until the first stage objective filling weight is reached, and then activating the opening/closing mechanism so as to close from the predetermined opening degree. A closing travel distance of the opening/closing mechanism in a certain minute time interval, and a filling weight of bulk material are then detected, and based on these detected values, the fluidity of the bulk material in such a minute time interval is calculated. A closing travel distance and a closing travel speed of the opening/closing mechanism in a next minute time interval is then calculated based on the fluidity so as to activate the opening/closing mechanism to close thereby filling the bulk material to the filling object until the objective filling weight is reached.

FIELD OF THE INVENTION

This invention relates to a method and an apparatus for filling bulk(powder and grain) material to a filling object such as a container andthe like.

BACKGROUND OF THE INVENTION

Examples of related bulk material filling apparatuses have beendisclosed in Japanese Patent Application Laid-Open No. (JP-A) 113362/79(first related art) and Japanese Patent Application Laid-Open No. (JP-A)52001/83 (second related art).

According to the first related art, first the volume of bulk material ismeasured with a massive filling measure and its weight thereof ismeasured with a measuring device. Then, the bulk material is pouredcontinuously in a small quantity through a small hole and when thepoured amount reaches an objective filling value, the small hole isclosed such that the filling operation is completed.

According to the second related art, the weight of a package product inwhich its filling of bulk material is completed is measured with aweight checker and the tendency in the supply amount thereof from a cupmeasuring device is controlled. At the same time, a bulk materialsurface detecting device is provided on the hopper and according tosignals output from this detecting device, the amount of bulk materialflowing into the hopper is adjusted.

However, the related arts have the following problems.

(1) In the first related art, the small throw-in of the bulk material isconducted using the small holes, thus if the characteristics of powderchange, the fluidity thereof is affected. Thus, if the fluidity thereofis deteriorated, the powder falling time is prolonged thereby reducingthe filling accuracy.

(2) In the second related art, a result of measured weight of thepackage product after the filling is completed is fed back to the nextfilling operation. The flow rate cannot be compensated at real time.Thus, in this second related art as well, if the fluidity of bulkmaterial changes, a high precision filling cannot be conducted.

(3) In both the first and second related arts, when the throw-in isterminated, the amount of bulk material (called falling amount Wh)existing in the air (falling height) from just below the outlet of astorage portion closed by the opening/closing device up to a fillingobject is considered. It is necessary to control the opening/closingdevice at a timing in which the filling weight W of bulk material filledin the filling object reaches W=W₀ -Wh (W₀ : objective amount). However,the falling height of bulk material varies depending on the size of acontainer which is the filling object. Thus, it is necessary to changethe closing timing of the opening/closing device for every containersize, so that a time required for changing a product type increases.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a methodfor filling bulk material to a filling object rapidly and at a highprecision.

The present invention provides for a method for filling bulk material,wherein after the bulk material is filled into a measure and the bulkmaterial in the measure is massively thrown into a container, thethrow-in amount of the bulk material per unit time is adjusted to besubstantially constant so as to conduct additional throw-in thereof. Theadditional throw-in amount thereof is approximated linearly with respectto time and then the additional throw-in is stopped based on theapproximation line and a predetermined filling weight.

Further according to the present invention, there is provided anapparatus for filling bulk material, comprising: a measure to be filledwith the bulk material; a filling means for filling the bulk material tothe measure; a throw-in means for throwing the bulk material filled inthe measure to a container; a transportation means having a measuringdevice, for carrying the container; and a control unit for approximatingthe additional throw-in amount thereof linearly with respect to time andactivating the throw-in means based on the approximated line and apredetermined filling weight.

Still further according to the present invention, there is provided amethod for filling bulk material, in which an objective filling weightfor filling bulk material stored in a storage portion to a fillingobject is divided to a first stage objective filling weight and a secondstage objective filling weight and which comprises:

a first stage filling step in which an opening/closing mechanismprovided on the storage portion is set to a predetermined opening degreeand the bulk material is filled from the storage portion to the fillingobject until the first stage objective filling weight is reached; and

a second stage filling in which the opening/closing mechanism isactivated so as to close from the specified opening degree, a closingtravel distance of the opening/closing mechanism in a certain minutetime interval and a filling weight of bulk material are detected, andbased on such detected values, a fluidity of the bulk material in such aminute time interval is calculated; and

a closing travel distance and a closing travel speed of theopening/closing mechanism in a next minute time interval are calculatedbased on the fluidity so as to activate the opening/closing mechanism toclose thereby filling the bulk material to the filling object until theobjective filling weight is reached.

Further according to the present invention, there is provided anapparatus for filling bulk material comprising:

a storage portion for storing bulk material;

an opening/closing mechanism disposed on the storage portion, forcontinuously adjusting the supply amount of the bulk material to besupplied from the storage portion to a filling object by anopening/closing action;

a travel distance detecting device for detecting an opening/closingtravel distance of the opening/closing device;

a weight detecting device for detecting a filling weight of the bulkmaterial to be filled into the filling object; and

a control unit for controlling the opening/closing operation of theopening/closing mechanism;

the control unit controlling according to a first stage filling step inwhich an opening/closing mechanism is set to a predetermined openingdegree and the bulk material is filled from the storage portion to thefilling object until the first stage objective filling weight isreached; and

a second stage filling in which the opening/closing mechanism isactivated so as to close from the specified opening degree, and afluidity of the bulk material in such a minute time interval iscalculated from a closing travel distance of the opening/closingmechanism and a filling weight of the bulk material, which are detectedby the travel distance detecting device and the weight detecting devicein a certain minute time interval;

a closing travel distance and a closing travel speed of theopening/closing mechanism in a next minute time interval are calculatedbased on the fluidity so as to activate the opening/closing mechanism toclose thereby filling the bulk material to the filling object until theobjective filling weight is reached.

Further, according to the present invention, there is provided a methodfor filling bulk material, for filling the bulk material stored in thestorage portion to the filling object by means of controlling theopening/closing operation of the opening/closing device disposed in thestorage portion and filling a specified initial filling amount at themassive throw-in stage, and then filling a remaining filling amount atthe small throw-in stage thereby completing filling up to an objectivefilling weight (W₀), the method comprising:

measuring a fall time (tτ) of the bulk material from an outlet openingof the storage portion to the filling object at the massive throw-instage;

measuring a flow rate (q) of the bulk material poured from the storageportion at the small throw-in stage;

calculating a falling amount (Wh) thereof existing in the air from justbelow the outlet opening of the storage portion closed by theopening/closing device up to the filling object according to Wh=q×tτ atthe small throw-in stage; and

determining a timing in which the filling amount (W) of the bulkmaterial filled in the filling object at the small throw-in stagereaches W=W₀ -Wh to be a closing timing of the opening/closing device.

Further according to the present invention, there is provided a methodfor filling bulk material wherein a fall time of the bulk material foruse in calculation of the falling amount is an average of fall timesmeasured in just nearby N cycle filling operation.

Further according to the present invention, there is provided anapparatus for filling bulk material comprising:

a storage portion for storing the bulk material;

an opening/closing device disposed on the storage portion foropening/closing the outlet opening of the storage portion;

a weight detecting device for detecting a filling weight of the bulkmaterial supplied from the storage portion to a filling object; and

a control unit for controlling the opening/closing operation of theopening/closing device, filling a specified initial filling amount atthe massive throw-in stage, and then filling a remaining filling amountat the small throw-in stage thereby completing filling up to anobjective filling weight (W₀);

the control unit receiving a result of detection from the weightdetecting device and calculating a falling amount (Wh) existing in theair from just below the outlet opening of the storage portion closed bythe opening/closing device up to the filling object at the smallthrow-in stage according to Wh=q×tτ, by measuring the fall time (tτ) ofthe bulk material from the outlet opening of the storage portion to thefilling object at the massive throw-in stage, and further measuring aflow rate (q) of the bulk material poured from the storage portion atthe small throw-in stage, and further determining a timing in which thefilling amount (W) of the bulk material filled in the filling object atthe small throw-in stage reaches W=W₀ -Wh to be a closing timing of theopening/closing device.

Further, according to the present invention, there is provided anapparatus for filling bulk material wherein a fall time of the bulkmaterial for use in calculation of the falling amount is an average offall times measured in just nearby N cycle filling operation.

According to the invention described above, the following operation (1)is attained.

(1) Because after the bulk material is filled into a measure and thebulk material in the measure is massively thrown into a container, thethrow-in amount of the bulk material per unit time is adjusted to besubstantially constant so as to conduct additional throw-in thereof, theadditional throw-in amount thereof is approximated linearly with respectto time and then the additional throw-in is stopped based on theapproximation line and a predetermined filling weight, and the fillingaccuracy of the bulk material into the container is enhanced.

According to the invention described above, the following operation (2)is also attained.

(2) Because in the first stage filling step, the opening/closingmechanism is opened to a predetermined opening degree and the bulkmaterial can be filled to the filling object until the first stageobjective filling weight is reached, the bulk material can be filledrapidly.

In the second stage filling, the opening/closing mechanism is activatedso as to close from the specified opening degree, and based on a closingtravel distance of the opening/closing mechanism in a certain minutetime interval and a filling weight of bulk material, a fluidity of thebulk material in such a minute time interval is calculated and measured,and further a closing travel distance and a closing travel speed of theopening/closing mechanism in a next minute time interval are calculatedbased on this fluidity so as to activate the opening/closing mechanismto close thereby filling the bulk material to the filling object. Asdescribed above, while the bulk material is being filled, the fluiditythereof is calculated and measured at real time and based on thisfluidity, the opening degree of the opening/closing mechanism iscontrolled so as to determine the full closing timing of theopening/closing mechanism, therefore it is possible to reduce the amount(falling amount) of bulk material existing between the opening/closingmechanism and the filling object when the opening/closing mechanism isfully closed, thereby realizing a high precision filling.

According to the invention described above, the following operations(3), (4) are also attained.

(3) Because at the massive throw-in stage, the opening/closing device isopened at a specified opening degree so that bulk material can be thrownmassively into the filling object up to a specified initial fillinglevel, the bulk material can be filled rapidly.

(4) At the small throw-in stage, the falling amount (Wh) of bulkmaterial existing in the air (falling height) from just below the outletopening of the storage portion closed by the opening/closing device upto the filling object is calculated and the opening/closing device iscontrolled so as to be closed at a timing in which the filling amount(W) of the bulk material filled in the filling object reaches W=W₀ -Wh.While the bulk material is being filled, the falling time and flow rateof the bulk material are measured at real time and based on thismeasuring result, the closing timing of the opening/closing device isdetermined. Thus, a high precision filling can be achieved without beingaffected by a change of the characteristics of the bulk material and anecessity for a time required for changing filling object types.

According to the invention described above, the following operation (5)is also attained.

(5) Because a fall time of the bulk material for use in calculation ofthe falling amount is an average of fall times measured in just nearby Ncycle filling operation, the filling accuracy can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention and many of the attendantadvantages thereof will be readably obtained as the same becomes betterunderstood by references to the following detailed description whenconsidered in connection with the accompanying drawings, wherein:

FIG. 1 is a side sectional view showing an embodiment of a fillingapparatus for filling bulk material to a container according to thepresent invention;

FIG. 2 is a side sectional view of an enlarged major portion of FIG. 1;

FIG. 3 is a diagram showing a relationship between the filling amount ofbulk material based on the output of a load cell base in the fillingapparatus and time according to the first embodiment;

FIG. 4 is a time table showing a filling process according to the firstembodiment of the filling method for filling bulk material to acontainer according to the present invention;

FIG. 5 is a plan sectional view of a major section showing a fillingprocess for filling bulk material to a container with the fillingapparatus according to the first embodiment;

FIGS. 6(a) to 6(f) are diagrams showing steps of the filling method forfilling bulk material to a container with the filling apparatusaccording to the first embodiment. FIG. 6(a) is a diagram of a sectionalview of a major section showing that bulk material is filled in eachmeasure, FIG. 6(b) is a sectional view of the major section showing astate in which a massive throwing-in is being conducted, FIG. 6(c) is asectional view of the major section showing an intermediate state(stabilized state) between the massive throwing-in and an additionalthrowing-in, FIG. 6(d) is a sectional view of the major section showinga state in which an additional throwing-in is being conducted, FIG. 6(e)is a sectional view of the major section showing a state in which theadditional throwing-in is completed, and FIG. 6(f) is a sectional viewof the major section showing a state in which bulk material is filled inthe measure;

FIG. 7 is a longitudinal sectional view of a rotary type fillingapparatus to which the second embodiment of the bulk material fillingcontrol unit according to the present invention is applied;

FIG. 8 is a sectional view taken along the line VII--VII of FIG. 7;

FIG. 9 is a fill timing chart in the rotary type filling apparatus shownin FIG. 7;

FIG. 10 is a sectional view showing an enlarged part of FIG. 7;

FIG. 11 is a perspective view showing schematically a filling hopper anda shutter shown in FIG. 10;

FIG. 12 is a graph showing a relationship between the weight of bulkmaterial for use at the first stage filling and the opening degree ofthe shutter;

FIG. 13 is a flow chart of filling control for bulk material;

FIGS. 14(a) and 14(b) are graphs showing a relationship between thefilling weight of bulk material and time;

FIG. 15 is a schematic view showing the third embodiment of the fillingapparatus;

FIG. 16 is a sectional view taken along the line XVI--XVI of FIG. 15;

FIG. 17 is a fill timing chart of the filling apparatus;

FIG. 18 is an enlarged view of the major section of FIG. 15;

FIG. 19 is a flow chart of filling control;

FIG. 20 is a linear diagram showing a filling time curve;

FIG. 21 is a linear diagram showing the major section of FIG. 20 indetail; and

FIG. 22 is a linear diagram showing a flow rate calculation method.

BEST PRACTICAL MODES OF THE INVENTION First Embodiment

Referring now to the drawings, wherein like reference numerals designateidentical or corresponding parts throughout the several views, FIGS. 1-3show a rotary type bulk material continuous filling apparatus of anembodiment of a filling apparatus for filling bulk material to acontainer according to the present invention. Referring to theseFigures, reference numeral 1 denotes a rotary type bulk materialcontinuous filling apparatus (hereinafter referred to as bulk materialfilling apparatus) and symbol C denotes a container.

As shown in FIG. 1, the bulk material filling apparatus 1 comprises amotor 3 loaded with a speed reducing unit, a driving shaft 4 which isrotated around its vertical axis by the motor 3 through bevel gears, aturn table (carrying means) 5 insertedly fixed to the driving shaft 4, acylinder base 6 insertedly fixed to the driving shaft 4 above the turntable 5 and a turret base 7 insertedly fixed to the driving shaft 4above the cylinder base 6 in a frame main body 2, respectively. A slipring 40 is fitted to the upper end of the driving shaft 4 so as tosupply electric power to a sequencer 9 described later.

Load cell bases (measures) 50 are disposed on the turn table 5 so as tobe able to measure weight of a container C being carried by convertingthe distortion amount of the load cell (not shown) of the load cell base50 to a weight. The output of the load cell 50 is amplified by a loadcell amplifier 51 and then supplied to the sequencer (control section) 9such that the container C being carried and the amount of bulk materialfilled within the container C can be monitored successively. The turntable 5 is provided with a supplying star wheel 52 for supplying acontainer C to the turn table 5 and a disfilling star wheel 53 fordistilling the container 5 from the turn table 5 (see FIG. 5)

An electric piston cylinder mechanism (throw-in means) 60 is disposed onthe cylinder base 6. This electric piston cylinder mechanism 60 has aservo motor 61 and a rod 62 which is activated by the servo motor 61.The servo motor 61 is controlled by the sequencer 9 described laterthrough a motor driver 63 so as to control the opening/closing of ashutter 81 of a measure 8 described later thereby adjusting the throw-inamount of bulk material. Cylindrical guides 64 are disposed on theperipheral portion of the cylinder base 6 so as to enhance the sealingbetween the shutter 81 and the container C, thereby suppressing flyingof bulk material at the time of massive throw-in. The guide 64 includesa window 64a (FIG. 2) which enables the shutter 81 to move back andforth.

The turret base 7 has a rising wall portion 71 (FIG. 2) which risesupward at the exterior peripheral portion of a base portion 70 which isof a circular shape as viewed on the plan. In the base portion 70, holes72 for the measure 8 described later are formed such that bulk materialis filled into the measure 8 through this hole 72.

Above the turret base 7, a bulk material supplying cylinder 73 forsupplying bulk material onto the turret base 7 is supported by the framemain body 2. In the intermediate portion in the radius direction of thebase portion 70, semi-circular guides 74, 75 are supportedly fixed bythe frame main body 2 through supporting means (not shown). The guide 74holds bulk material supplied from the bulk material supplying cylinder73 within a specified area of the base portion 70 and cuts the upperface of bulk material filled in the measure 8 so as to be flush with thesurface of the base portion 70 as the turret base 7 rotates. The guide75 holds bulk material aside of the peripheral portion of the baseportion 70. Here, the turret base 7, the bulk material supplyingcylinder 73 and the respective guides 74, 75 constitute a throw-in means76.

The turret base 7 includes the measures 8 insertedly disposed thereon.Each of the measures 8 comprises a cylindrical sleeve 80 which is itsbody and the shutter 81 which is its bottom portion. The shutter 81 isconnected to the rod 62 of the electric piston cylinder mechanism 60 andreciprocated by the back and forth movement of the rod 62 so as toopen/close the bottom opening portion of the sleeve 80.

The sequencer 9 is mounted substantially in the center portion of theturret base 7. The sequencer 9 monitors the filling amount of bulkmaterial in the container C based on the output from the load cell 50and dispatches an operation command for closing the shutter 81 to theservo motor 61 of the electric piston cylinder mechanism 60 based on theoutput of the load cell base 50.

The operation command of the servo motor 61 by the sequencer 9 based onthe output of the load cell base 50 is dispatched as shown in FIG. 3.That is, first the shutter 81 of the measure 8 is moved to open thebottom portion of the measure 8 to throw in massively bulk materialstored in the measure 8 up to about 70% relative to a predeterminedfilling amount W. Next, the extent of the opening of the measure 8 bythe shutter 81 is narrowed after this massive throw-in and then bulkmaterial is additionally thrown in with a throw-in amount per unit timeW' substantially fixed. According to real-time output from the load cellbase 50, the additional throw-in amount is approximated linearly andthen based on this approximated line L and the set filling amount W, thefilling complete time T by additional throw-in is calculated byarithmetic operation. At T' obtained by subtracting t needed for bulkmaterial to be additional thrown in to reach the container C from themeasure 8 from this filling complete time T, the shutter 81 is closed tostop additional throw-in, so that bulk material of the set fillingamount W is filled in the container C. Here, an interval (time) A inwhich the additional throw-in amount is approximated linearly relativeto time is 0.2-1.0 seconds or preferably 0.5-0.6 seconds.

Next, the means of the filling method for filling bulk material to acontainer according to the present invention will be described withreference to a time chart shown in FIG. 4 and FIGS. 5, 6 based on theexecution of the bulk material filling apparatus 1. The descriptionbelow will be represented based on a single unit of the measure 8. Theunit of numeric values in FIG. 4 is seconds.

First, empty containers C are carried by means of a transportationconveyor 100 and a pitch adjusting device 101 and loaded on the loadcell 50 of the turn table 5 by the supplying star wheel 52. When 0.2seconds pass after the container C is loaded on the load cell base 50,monitoring of a measured value by the load cell base 50 which isconducted by the sequencer 9 is started. In the upstream of thiscontainer, bulk material is always being filled into the measure 8 (seeFIGS. 4, 5 and 6(a)).

Next, after the container C is loaded on the load cell base 50, theservo motor 61 is activated by an operation command from the sequencer 9such that the shutter 81 is moved to open the bottom end of the measure8 for a second. Then, about 70% the predetermined filling amount W ofbulk material filled in the measure 8 is massively thrown into thecontainer C (see FIGS. 4, 5 and 6(b)).

After the massive throw-in of bulk material, the shutter 81 is moved byan operation command from the sequencer 9 such that the opening state ofthe measure 8 is narrowed. In this interval of 0.5 seconds, thevibration of the load cell base 50 is stabilized, the top end of bulkmaterial in the measure 8 is cut by the guide 74 and a further supply ofbulk material into the measure 8 is restricted. Then, the throw-inamount of bulk material per unit time is made substantially constant andadditional throw-in of the bulk material is conducted for 1.5 seconds.During this time, in the sequencer 9, the additional throw-in amount ofthe bulk material based on the real-time output of the load cell base 50is approximated linearly. Then, the sequencer 9 calculates the time T upto a completion of the filling by the additional throw-in based on thisapproximated line L and the predetermined filling amount W by arithmeticoperation. Then, the shutter 81 is closed at T' obtained by subtractingtime t in which bulk material thrown in additionally reaches thecontainer C from the measure 8, from this time T up to the completion ofthe filling, so as to stop the additional throw-in, such that thepredetermined filling amount W of bulk material is filled into thecontainer C (see FIGS. 4, 5, 6(d), (e)).

After the specified additional throw-in of bulk material is completed,the container C is introduced to the distilling conveyor 102 by thedisfilling star wheel 53 and further transported to a successive processfor a packaging process or the like (see FIGS. 5 and 6(f)).

As evident from the above description, use of the bulk material fillingapparatus 1 according to this embodiment and the filling method forfilling bulk material to a container using this apparatus enables a highprecision filling to be conducted continuously in a short time.

Further, the bulk material filling apparatus 1 opens and closes theshutter 81 by means of the electric piston cylinder mechanism 60 and themassive throw-in and the additional throw-in are conducted by theshutter 81. Thus, as compared to a conventional damper typeopening/closing operation, the present invention can achieve a moreaccurate opening/closing operation and can simplify the construction ofthe measure more than in related art.

Meanwhile, the filling apparatus for filling bulk material to acontainer according to the present invention is not restricted to theabove described embodiment.

For example, it is permissible to use a so-called line type intermittentfeeding apparatus in which the respective steps in the rotary type bulkmaterial continuous filling apparatus 1 are distributed linearly insteadof the former. In this case as well, it is needless to say that the sameoperation and effect as in the above case can be obtained.

The shape of the measure is not restricted to the cylindrical shape asdescribed in the above embodiment but may be an elliptic cylinder, arectangular cylinder, a triangular cylinder or the like.

Further, the shutter 81 is not restricted to any particular type as longas it has a function of throwing in bulk material into a container Cmounted therebelow and may be a both-side withdrawal type, a three-waywithdrawal type or the like, as long as the throw-in amount thereof canbe controlled by the amount of its stroke.

Further, it is needless to say that the filling method for filling bulkmaterial to a container according to the present invention is notrestricted to an execution of the aforementioned embodiment by the bulkmaterial filling apparatus 1.

Second Embodiment

In a rotary type filling apparatus 110 as shown in FIG. 7, a pluralityof the containers C as an object to be filled are installed on a disc(second base 112). While this disc is rotated, bulk material such aspowder is gradually filled into respective containers C. This rotarytype filling apparatus 110 comprises a turn table 113 acting as astorage portion, filling hoppers 114, first base 111, second base 112,shutters 115 acting as an opening/closing device, an encoder 116 fordetecting a travel distance of load cells 117 for detecting weights, anda control unit 118.

The turn table 113, the first base 111 and the second base 112 are fixedto a rotating shaft 119. The rotating shaft 119 is communicated with adriving motor 120 through a first bevel gear 121 and a second bevel gear122 which mesh with each other. Thus, the turn table 113, the first base111 and the second base 112 are rotated synchronously by means of thedriving motor 120. The turn table 113, the first base 111, the secondbase 112, the rotating shaft 119, the driving motor 120 and the like areconstructed so as to be surrounded by a casing 123.

The turn table 113 is capable of storing powder and has a plurality ofthe filling hoppers 114 disposed along the circumference thereof. Thecasing 123 has a powder supplying cylinder 124, from which powder issupplied into the turn table 113 and stored thereon. A plate 125 forsuppressing flying of bulk material is provided under the powdersupplying cylinder 124 to suppress flying of bulk material whensupplying.

As the turn table 113 rotates, powder supplied from the powder supplyingcylinder 124 thereto and stored thereon is forced outward in thediameter direction of the turn table 113 by the action of a force-outguiding plate 126 as shown in FIG. 8 and filled into the filling hoppers114. Further, the action of a scratching plate 127 prevents a supplythereof to the filling hoppers 114.

While powder is supplied to the filling hoppers 114 by the force-outguiding plate 126, filling of bulk material at the first stage whichwill be described later is conducted. While forcing powder outward bythe force-out guiding plate 126 is conducted and then it is scratched bythe scratching plate 127, filling thereof at the second stage which willbe described later is conducted.

As shown in FIG. 7, a plurality of the filling hoppers 114 are disposedsuch that the outlet openings thereof can be opened and closedindividually by a plurality of the shutters 115. As shown in FIG. 10,shutter activating devices 128 for activating the shutters 115 aredisposed on the first base 111. The shutter activating device 128comprises an electric cylinder 129 driven by a servo motor and a motordriver 130. The motor driver 130 is activated by a command from thecontrol unit 118 to drive the electric cylinder 129 thereby determiningthe opening degree of the shutter 115. By changing an opening degreedetermined by the shutter activating device 128, the shutter 115 iscapable of continuously adjusting the supply amount (filling weight) ofpowder to be filled into the container C from the filling hopper 114.The electric-driven cylinder 129 is equipped with the encoder 116 fordetecting a travel distance X for the opening/closing operation of theshutter 115 and this detected value X is output to a control unit 118.

The second base 112 has a plurality of the load cells 117 disposed atrespective positions corresponding to each of the filling hoppers 114and the shutters 115. The containers C are placed on the load cells 117.The filling weight W of powder to be filled into the container C isdetected by the load cell 117 and such a detected value W is output tothe control unit 118.

Meanwhile, the first base 111 has powder flying preventive plates 131which surround the outlet of each of the filling hoppers 114 and each ofthe shutters 115 so as to prevent powder from flying and scattering whenpowder is thrown into the container C from the filling hopper 114thereby enhancing sealing performance between the filling hopper 114 andthe container C.

As shown in FIG. 8, the container C is mounted on a transportationconveyor 132 and transported thereby and the transportation pitch of thecontainer C is adjusted by a pitch adjusting device 133. Then thecontainer C is carried onto the load cell 117 of the second base 112 bymeans of a supplying side star wheel 134. After the container C isfilled with powder, it is sent out from the load cell 117 of the secondbase 112 to the transportation conveyor 132 by means of the disfillingside star wheel 135.

The control unit 118 controls the opening/closing operation of a shutter115 through a shutter operating mechanism 128, determines the degree ofthe opening of the shutter 115 at real time and fills powder to acontainer C from a filling hopper 114. A travel distance X of theshutter 115 at an arbitrary time is input to the control unit 118 fromthe encoder 116 and further a powder filling weight W to the container Cat an arbitrary time is input thereto from the load cell 117. Thiscontrol unit 118 contains an objective filling amount Wp of powder to befilled into a single container, a predetermined ratio α of the firststage objective filling amount Wp₁ (described later) relative to thisWp, a linear approximation data L as shown in FIG. 12 indicating arelationship between the travel distance X of the shutter 115 and thefilling weight W of powder to be filled into the container C, and aninverse function F(S) determined by the shape of the outlet shape of thefilling hopper 114. This inverse function F(S) is fixed as follows,because as shown in FIG. 11, the change rate AS of the outlet openingarea S of the filling hopper 114 in the interval of a minute time isdetermined as a function of the change rate AX of the travel distance Xof the shutter 115 in this while:

    F(S)=X/S                                                   (1)

Here, a measuring method for the fluidity Uρ of powder will bedescribed. In FIG. 11, assuming that the change rate of the traveldistance of the shutter 115 in the interval of a minute time Δt is ΔX,the change rate of the outlet opening area of the filling hopper 114 isΔS, the drop velocity of powder is U, and the specific gravity of powderis ρ, the change rate ΔQ of the filling weight of powder to be filled bypowder dropping to the container C in this minute interval of time Δt isdetermined as follows:

    ΔQ=ΔS(X)×U×Δt×ρ    (2)

The ΔQ can be obtained from the filling weight W of powder measured bythe load cell 117, the ΔS(X) can be obtained from the travel distance Xof the shutter 115 measured by the encoder 116 and the Δt has beenpreliminarily determined as a sampling interval. Thus, the fluidity Uρof powder in this minute interval of time Δt can be measured accordingto the following expression (3).

    Uρ=ΔQ/(ΔS(X)×Δt)               (3)

If the ΔS(X) is eliminated using the above expressions (1), (2), thefollowing expression can be obtained.

    X={ΔQ/Uρ×Δt}×F(S)              (4)

As a result, the travel distance X of the shutter 115 can be obtained.

The fluidity Uρ of powder varies depending on the size of the particlesof bulk material, percentage of voids of the powder particles, the shapeof the powder particles, specific gravity of the powder, temperature andhumidity in the filling hopper 114, the powder flying preventive plate131 and the container C, and friction of the walls of the filling hopper114, the powder flying preventive plate 131, and the container C, andthe flow condition of air in the filling hopper 114, the powder flyingpreventive plate 131 and the container C and the like. This fluidity Uρof powder affects the accuracy in weight of powder to be filled when thepowder is thrown into the container C from the filling hopper 114.

Meanwhile, the control unit 118 executes filling of the first and secondstages when filling of powder from the filling hopper 114 into thecontainer C is started (step (1) in FIG. 13).

At the first stage filling, the control unit 118 calculates a firststage objective filling weight Wp₁ from an objective filling weight Wpand the predetermined ratio α according to the expression (5) below(step (2)).

    Wp.sub.1 =Wp×α                                 (5)

Here, the predetermined ratio a is, for example, 98%. Next, the controlunit 118 calculates a travel distance (specified opening degree) X₁ ofthe shutter 115 corresponding to the first stage objective fillingweight Wp₁ from the linear approximation data L shown in FIG. 12 (step(3)) and moves the shutter 115 at a specified speed (for example, X₁ /1m/sec) up to a travel distance X₁ (step (4)) to fill powder at a massiveflow rate into the container C. In this while, the load cell 117measures the filling weight W in the interval of the minute time Δt(e.g. 10 mmsec) as shown in FIG. 14(A) and this measured value W isentered into the control unit 118 (step (5)).

At the first stage filling, when the measured value of the fillingweight W in the container C which is to be measured by the load cell 117exceeds the first stage objective filling weight Wp₁, the control unit118 closes the shutter 115 from the specified opening degree X₁ so as tochange over from the first stage filling to the second stage filling(step (6), (7)). This change-over time is first stage filling completiontime and further second stage filling start up time. This change-overtime is assumed to be t₁.

Because the measured value W(t₁) by the load cell 117 at thischange-over time t₁ is W(t₁), the control unit 118 calculates the secondstage objective filling weight Wp₂ according to the expression below (6)(step (8)).

    Wp.sub.2 =Wp-W(t.sub.1)                                    (6)

Further, the control unit 118 sets the travel distance X (t₂) for theclosing operation of the shutter 115 in order to move the shutter 115from this time t₁ to next time t₂ which is ahead by the minute time Atand the travel speed V(t₂) of the shutter 115 as follows:

    X (t.sub.2)=initial travel distance a (a=1 mm)

    V (t.sub.2)=a/Δt

Meanwhile, the reason why the measured value of the load cell 117 dropsat time t₁ as shown in FIGS. 14(a) and 14(b) is due to an influence ofthe acceleration applied to powder at the first stage filling and thatthe measured value of the load cell 117 indicates a higher value than anactual filling weight.

At the time t₂ of the second stage filling, based on the traveldistances X(t₁), X(t₂) of the shutter 115 at the respective times t₁, t₂measured by the encoder 116, the control unit 118 calculates a changerate of the outlet opening area of the filling hopper 114 in this whileas follows:

    ΔS(X(t.sub.2)-X(t.sub.2))

Further, based on the filling weights W(t₁), W(t₂) detected by the loadcell 117 at the respective times t₁, t₂, the control unit 118 calculatesa change rate ΔQ(t₂) of the filling weight of powder in this while asfollows:

    ΔQ(t.sub.2)=W(t.sub.2)-W(t.sub.1)

Thus, the control unit 118 calculates the fluidity Uρ (t₂) of powder inan interval from time t₁ to time t₂ using these values according to theexpression (3), as follows:

    Uρ(t.sub.2)=ΔQ(t.sub.2)/{ΔS(X(t.sub.2)-X(t.sub.1))×.DELTA.t}(step (9))

At time t₂, the control unit 118 calculates the closing travel distanceX(t₃) and travel speed V(t₃) of the shutter 115 to be moved in aninterval of minute time Δt up to next time t₃, based on the fluidity Uρ(t₂) according to the expression (4) as follows:

    X(t.sub.3)=[{Wp.sub.2 -(W(t.sub.2)-W(t.sub.1))}/Uρ(t.sub.2)×Δt]×F(s)

    V(t.sub.3)=X(t.sub.3)/Δt (step (10))

Likewise, at the second stage filling time t₃, the control unit 118calculates a change rate of the outlet opening area of the fillinghopper 114 in an interval of minute time At from time t₂ to time t₃,according to;

    ΔS(X(t.sub.3)-X(t.sub.2))

and a change rate of the filling weight of the powder in this whileaccording to;

    ΔQ(t.sub.3)=W(t.sub.3)-W(t.sub.2)

Then, the control unit 118 calculates the fluidity Uρ (t₃) of thispowder in an interval of minute time Δt from time t₂ to time t₃according to the following expression;

    Uρ(t.sub.3)=ΔQ(t.sub.3)/{ΔS(X(t.sub.3)-X(t.sub.2))×.DELTA.t}

Based on this fluidity Uρ (t₃) of the powder, the control unit 118calculates the closing travel distance X (t₄) and travel speed V(t₄) ofthe shutter 115 to be moved in an interval of minute time from Δt timet₃ to next time t₄, using the expression (4) according to the followingexpression.

    X(t.sub.4)=[{Wp.sub.2 -(W(t.sub.3)-W(t.sub.1))}/Uρ(t.sub.3)×Δt]×F(S)

    V(t.sub.4)=X(t.sub.4)/Δt

The control unit 118 conducts arithmetic operation up to time t_(n) inthe same manner and at time tn, calculates a change rateΔ(S(X(t_(n))-X(t_(n-1))) of the outlet opening area of the fillinghopper 114 in an interval from time t_(n-1) to time t_(n) and a changerate ΔQ(t_(n))=W(t_(n))-W(t_(n-1)) of the filling weight of the powderin this while, and further calculates and measures the fluidityUρ(t_(n)) of powder in an interval of minute time Δt from that timet_(n-1) to time t_(n), according toUρ(t_(n))=ΔQ(t_(n))/{S(X(t_(n))-X(t_(n-1)))×.DELTA.t}. Based on thefluidity Uρ(t_(n)) of this bulk material 2, the control unit 118calculates the closing travel distance X(t_(n+1)) and travel speedV(t_(n+1)) of the shutter 115 to be moved in an interval of minute timeΔt from time t_(n) to next time t_(n+1) using the expression (4)according to the following expression;

    X(t.sub.n+1)=[{Wp.sub.2 -(W(t.sub.n)-W(t.sub.1)}/Uρ(t.sub.n)×Δt]×F(S)

    V(t.sub.n+1)=X(t.sub.n+1)/t

The control unit 118 repeats the above described second stage fillingoperation until the filling weight applied from the second stage fillingstart up time t₁ to an arbitrary time t_(n) coincides with Wp₂, that is,until as shown in FIG. 14(b), the filling weight applied up to anarbitrary time t_(n) coincides with an objective filling weight Wp, inother words, until Wp₂ -(W(t₂)-W(t₁))=Wp-W(t_(n))→0 (step (11)). If theabove coincidence is attained, the shutter 115 is made to close fullysuch that the filling of powder is terminated (step (12)).

In the rotary type filling apparatus 110 having the constructiondescribed above, for example as shown in FIG. 9, the turn table 113 andthe first base 111 and the second base 112 make a single turn in 4seconds and the weight of the container C carried to the load cell 117of the second base 112 from the supplying side star wheel 134 isdetected by the load cell 117 in the first 0.2 seconds. In the next 0.1seconds, filling at the first stage from the filling hopper 114 to thecontainer C is conducted such that rapid filling at a massive fillingrate is achieved. In the next 0.2 seconds, filling at the second stagefrom the filling hopper 114 to the container C is conducted such that ahigh precision filling at a minute filling rate is achieved. Then, thecontainer C in which powder is fully filled is carried out to thetransportation conveyor 132 by means of the disfilling side star wheel135 in 0.24 seconds and in the next 0.56 seconds, no container C isplaced on the load cell 117.

According to the above described embodiment, because the shutter 115 isopened up to a specified opening degree X₁ at the first stage fillingsuch that the powder can be massively filled into the container C up toits first stage objective filling weight Wp₁, the powder can be filledrapidly.

Further, at the second stage filling, the shutter 115 is activated so asto be closed from its specified opening degree X₁. According to thechange rate ΔS of the outlet opening area of the filling hopper 114 andthe change rate ΔQ of the filling weight W of powder, based on theclosing travel distance X of the shutter 115 in an interval of a certainminute time Δt, the fluidity Uρ of bulk material in the interval of thatminute time Δt is calculated at real time. Then, based on this fluidityUρ, the closing travel distance X and the closing travel speed V of theshutter 115 in a next interval of minute time Δt are calculated and theshutter 115 is closed such that the filling is completed. As describedabove, because the fluidity Uρ of powder is calculated and measured atreal time while it is being filled and based on this fluidity Uρ, theopening degree of the shutter 115 is controlled so as to determine thefull closing timing of the shutter 115. Thus, it is possible to reducethe amount of powder existing between the shutter 115 and the containerC to a minimum extent particularly when the shutter 115 is operated soas to be closed fully, so that a high precision filling can be achieved.

Although a case of powder is described as bulk material in the abovedescribed embodiment, the same operation can be attained in a case ofgrain. Further, although a case of the rotary type filling apparatus isdescribed in this embodiment, it is possible to apply the presentinvention to the other filling apparatus.

Third Embodiment

In a rotary type filling apparatus 210 as shown in FIG. 15, a pluralityof the containers C as an object to be filled are installed on a disc(second base 212). While this disc is rotated, bulk material such aspowder is gradually filled into respective containers C. This rotarytype filling apparatus 210 comprises a turn table 213 acting as astorage portion, filling hoppers 214, a first base 211, the second base212, shutters 215 acting as an opening/closing device, load cells 217for detecting weights, and a control unit 218.

The turn table 213, the first base 211 and the second base 212 are fixedto a rotating shaft 219. This rotating shaft 219 is communicated with adriving motor 220 through a first bevel gear 221 and a second bevel gear222 which mesh with each other. Thus, the turn table 213, the first base211 and the second base 212 are rotated synchronously by means of thedriving motor 220. The turn table 213, the first base 211, the secondbase 212, the rotating shaft 219, the driving motor 220 and the like areconstructed so as to be surrounded by a casing 223.

The turn table 213 is capable of storing powder and has a plurality ofthe filling hoppers 214 disposed along the circumference thereof. Thecasing 223 has a powder supplying cylinder 224, from which powder issupplied into the turn table 213 and stored thereon.

As the turn table 213 rotates, powder supplied from the powder supplyingcylinder 224 thereto and stored thereon is forced outward in thediameter direction of the turn table 213 by the action of a force-outguiding plate 226 as shown in FIG. 16 and filled into the fillinghoppers 214. Further, the action of a scratching plate 227 prevents asupply thereof to the filling hoppers 214.

While powder is supplied to the filling hoppers 214 by the force-outguiding plate 226, filling of bulk material at the massive throw-instage which will be described later is conducted. While forcing powderoutward by the force-out guiding plate 226 is conducted and then it isscratched by the scratching plate 227, filling thereof at the smallthrow-in stage which will be described later is conducted.

As shown in FIG. 15, a plurality of the filling hoppers 214 are disposedsuch that the outlet openings thereof can be opened and closedindividually by a plurality of the shutters 215. As shown in FIG. 18,shutter activating devices 228 for activating the shutters 215 aredisposed on the first base 211. This shutter activating device 228comprises an electric cylinder 229 driven by a servo motor and a motordriver 230. This motor driver 230 is activated by a command from thecontrol unit 218 to drive the electric cylinder 229 thereby determiningthe opening degree of the shutter 215. By changing an opening degreedetermined by the shutter activating device 228, this shutter 215 iscapable of adjusting continuously the supply amount (filling weight) ofpowder to be filled into the container C from the filling hopper 214.That is, the control unit 218 controls so as to supply a specifiedinitial filling amount of powder massively with the shutter 215 openedat a massive opening degree at the massive throw-in stage, and thensupply a remaining filling amount thereof at a small flow rate at thesmall throw-in stage thereby completing a filling of an objectivefilling weight (W₀) of powder in the container C.

The second base 212 has a plurality of the load cells 217 disposed atrespective positions corresponding to each of the filling hoppers 214and the shutters 215. The containers C are placed on the load cells 217.The filling weight W of powder to be filled into the container C isdetected by the load cell 217 and such a detected value W is output tothe control unit 218.

Meanwhile, the first base 211 has powder flying preventive plates 231which surround the outlet of each of the filling hoppers 214 and each ofthe shutters 215 so as to prevent powder from flying and scattering whenpowder is thrown into the container C from the filling hopper 214thereby enhancing the sealing performance between the filling hopper 214and the container C.

As shown in FIG. 16, the container C is mounted on a transportationconveyor 232 and transported thereby and the transportation pitch of thecontainer C is adjusted by a pitch adjusting device 233. Then thecontainer C is carried onto the load cell 217 of the second base 212 bymeans of a supplying side star wheel 234. After the container C isfilled with powder, it is sent out from the load cell 217 of the secondbase 212 to the transportation conveyor 232 by means of the disfillingside star wheel 235.

The filling amount control operation by the control unit 218 isconducted as follow (see FIG. 19).

(A) Massive throw-in stage (FIG. 20)

The initial filling weight at the massive throw-in stage is assumed tobe a (e.g. 98%) relative to the objective filling weight (W₀).

(1) The shutter 215 is opened by the shutter activating device 228.Then, the shutter 215 is kept at a specified large opening degree (step(1)).

(2) A fall time measuring timer is started at a shutter 215 openingstart timing (step (2)). When the load cell 217 detects a weight ofpowder (step (3)), the fall time measuring timer is stopped and a falltime (tτ) of powder which falls from the outlet opening of the fillinghopper 214 into the container C is output (step (4)). This fall time(tτ) is memorized in a memory (step (5)).

Meanwhile, the control unit 218 utilizes the average value of the falltimes measured at a filling operation of just nearby N cycle andmemorized in the memory as the fall time described above for use incalculation of a falling amount which will be described later.

(3) If such a detected value by the load cell 217 reaches the initialfilling weight (W₀ ×α) at the massive throw-in stage, the opening degreeof the shutter 215 is adjusted to a specified small opening degree bythe shutter activating device 228. (steps (6), (7))

The reason why after the opening degree of the shutter 215 is changed toits small opening degree, the value detected by the load cell 217 dropswith respect to its peak value as shown in FIG. 20 is that the fallacceleration of powder is applied to the load cell 217 when it strikesthe load cell 217 such that the value measured by the load cell 217exceeds the actual weight of powder already filled in the container C.

(B) Small throw-in stage (FIGS. 20, 21)

(1) After the opening degree of the shutter 215 is changed to its smallopening degree, the detected values W(T_(n+1)), W(T_(n)) of the loadcell 217 at the filling times T_(n+1), T_(n) indicate a followingrelationship due to the action of the application of the fallacceleration of the powder described above,

    W(T.sub.n+1)-T.sub.n <0                                    (1)

and it is recognized that the detected value of the load cell 217exceeds its peak value as described above.

Then, after the above relationship (1) is attained, it is recognizedthat the massive throw-in stage has been changed to the small throw-instage with;

    W(T.sub.n+1)-T.sub.n >|A|                (2)

Where, for example, A=10 g, sampling frequency is 10 msec.

Further, after the above expression (2) is established, the detectedvalue of the load cell 217 for example when amsec (safety ratio time forconfirming that the stable linear area has been attained) has passed isdetected as Wsp in which the linear application at the small throw-instage has been started. (step (8)).

(2) A flow rate q of powder made to flow from the filling hopper 214 ismeasured (step (9)). Based on Wsp, a detected value Wtp of the load cell217 when bmsec has passed is obtained. (FRIG. 22) The flow rate q isdetermined as follows.

    q=(Wtp-Wsp)/b                                              (3)

Thus, if a passed time since Wsp is reached is assumed to be t, thefilling weight W to the container C is;

    W=[((Wtp-Wsp)/b]×t+Wsp                               (4)

(3) The falling amount Wh existing in the air from just below the outletopening of the filling hopper 214 closed by the shutter 215 to thecontainer C is calculated from the previously mentioned fall time (tτ)and the flow rate (q) according to;

    Wh=[(Wtp-Wsp)/b]×tτ                              (5) (step (5))

(4) The closing timing of the shutter 215 is calculated (step (11)). Thetiming in which the filling weight W filled to the container C at thesmall throw-in stage reaches

    W=W.sub.0 -Wh                                              (6)

is assumed to be the closing timing of the shutter 215. If the aboveexpression (6) is substituted for the expression (4), the closing timingt is;

    t=(W.sub.0 -Wh-Wsp)×b/(Wtp-Wsp)                      (7)

(5) Based on the closing timing t calculated in (4) above, the closingtiming timer value is set (step (12)). Then, the closing timing timer isstarted (step (13)) and when the measured value of the closing timingtimer reaches its set value (step (14)), the shutter 15 is closed (step(15) and then the filling operation is completed.

In the rotary type filling apparatus 210 having the constructiondescribed above, for example as shown in FIG. 17, the turn table 213 andthe first base 11 and the second base 212 make a single turn in Tseconds and the weight of the container C carried to the load cell 217of the second base 212 from the supplying side star wheel 234 isdetected by the load cell 217 in first t₁ seconds. In the next t₂seconds, filling at the massive throw-in stage from the filling hopper214 to the container C is conducted such that rapid filling at a massivefilling rate is achieved. In the next t₃ seconds, filling at the smallthrow-in stage from the filling hopper 214 to the container C isconducted such that a high precision filling at a minute filling rate isachieved. After a stable interval of t₄ (allowance time), the containerC in which powder is fully filled is carried out to the transportationconveyor 232 by means of the distilling side star wheel 235 in t5seconds and in the next t6 seconds, no container C is placed on the loadcell 217.

Thus, the following operations (1)-(3) are attained according to thepresent embodiment.

(1) Because the shutter 215 is opened at a specified opening degree atthe massive filling stage and powder can be massively filled to thecontainer C up to the initial filling weight, rapid filling of powdercan be done.

(2) At the small filling stage, the amount of powder (falling amount Wh)existing in the air (falling height) from just below the outlet openingof the filling hopper 214 closed by the shutter 215 to the container Cis calculated and the shutter 215 is closed at the timing in which thefilling weight (W) of powder fully filled in the container C reachesW=W₀ -Wh. While powder is being filled, the fall time tr and flow rate qof powder are measured at real time and based on such a measured value,the closing timing of the shutter 215 is determined. Thus, a highprecision filling can be achieved without being affected by a change ofthe characteristics of powder and a necessity of container C typechange-over time.

(3) By adopting the fall time tτ of powder for use in calculation of thefalling amount Wh as an average of the fall time tτ measured in justnearby N cycle filling operation, the filling accuracy can be improved.

Although a case of powder is described as bulk material in the abovedescribed embodiment, the same operation can be attained in a case ofgrain. Further, although a case of the rotary type filling apparatus isdescribed in this embodiment, it is possible to apply the presentinvention to other filling apparatuses.

INDUSTRIAL APPLICABILITY

As described above, according to the method and apparatus for fillingbulk material, when bulk material such as detergent, bleaching agent,solvent, chemical and the like are filled into containers, such bulkmaterial can be filled to a filling object rapidly and at a highprecision.

Obvious numerous modifications and variations of the present inventionare possible in light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described herein.

What is claimed is:
 1. A method for filling bulk material, in which anobjective filling weight for filling bulk material stored in a storageportion to a filling object is divided to a first stage objectivefilling weight and a second stage objective filling weight, the methodcomprising:a first stage filling step which comprises setting anopening/closing mechanism provided on said storage portion to apredetermined opening degree and filling the bulk material from saidstorage portion to said filling object until said first stage objectivefilling weight is reached; a second stage filling step which comprisesactivating said opening/closing mechanism so as to close from saidpredetermined opening degree, detecting a closing travel distance ofsaid opening/closing mechanism in a certain minute time interval and afilling weight of bulk material, and based on said detected values,calculating a fluidity of the bulk material in such a minute timeinterval; and a step of calculating a closing travel distance and aclosing travel speed of said opening/closing mechanism in a next minutetime interval based on the fluidity so as to activate saidopening/closing mechanism to close thereby filling the bulk material tosaid filling object until said objective filling weight is reached. 2.An apparatus for filling bulk material, the apparatus comprising:astorage portion for storing bulk material; an opening/closing mechanismdisposed on said storage portion, for continuously adjusting a supplyamount of the bulk material to be supplied from said storage portion toa filling object by an opening/closing action; a travel distancedetecting device for detecting an opening/closing travel distance ofsaid opening/closing device; a weight detecting device for detecting afilling weight of the bulk material to be filled into said fillingobject; and a control unit for controlling an opening/closing operationof said opening/closing mechanism; said control unit controllingaccording to a first stage filling in which the opening/closingmechanism is set to a predetermined opening degree and the bulk materialis filled from said storage portion to said filling object until a firststage objective filling weight is reached; and a second stage filling inwhich said opening/closing mechanism is activated so as to close fromsaid predetermined opening degree, and a fluidity of the bulk materialin such that a minute time interval is calculated from a closing traveldistance of said opening/closing mechanism and a filling weight of thebulk material, which are detected by said travel distance detectingdevice and said weight detecting device in a certain minute timeinterval; and a closing travel distance and a closing travel speed ofsaid opening/closing mechanism in a next minute time interval arecalculated based on the fluidity so as to activate said opening/closingmechanism to close thereby filling the bulk material to said fillingobject until said objective filling weight is reached.
 3. A method forfilling bulk material for filling the bulk material stored in a storageportion to a filling object by means of controlling an opening/closingoperation of an opening/closing device disposed in said storage portionand filling a specified initial filling amount at a massive throw-instage, and then filling a remaining filling amount at a small throw-instage thereby completing filling up to an objective filling weight (W₀),said method comprising the step of:measuring a fall time (tτ) of thebulk material from an outlet opening to the filling object at saidmassive throw-in stage; measuring a flow rate (q) of the bulk materialpoured from the storage portion at said small throw-in stage;calculating a falling amount (Wh) thereof existing in air from justbelow the outlet opening of the storage portion closed by theopening/closing device up to the filling object according to Wh=q×tτ atthe small throw-in stage; and determining a timing in which the fillingamount (W) of the bulk material filled in the filling object at saidsmall throw-in stage reaches W=W₀ -Wh to be a closing timing of theopening/closing device.
 4. A method for filling bulk material accordingto claim 3, wherein a fall time of the bulk material for use incalculation of said falling amount is an average of fall times measuredin a just nearby N cycle filling operation.
 5. An apparatus for fillingbulk material comprising:a storage portion for storing bulk material; anopening/closing device disposed on said storage portion foropening/closing an outlet opening of said storage portion; a weightdetecting device for detecting a filling weight of the bulk materialsupplied from said storage portion to a filling object; and a controlunit for controlling an opening/closing operation of saidopening/closing device, filling a specified initial filling amount at amassive throw-in stage, and then filling a remaining filling amount at asmall throw-in stage thereby completing filling up to an objectivefilling weight (W₀), said control unit receiving a result of detectionfrom the weight detecting device and calculating a falling amount (Wh)existing in air from just below the outlet opening of the storageportion closed by the opening/closing device up to the filling object atsaid small throw-in stage, according to Wh=q×tτ by measuring a fall time(t T ) of the bulk material from the outlet opening of the storageportion to the filling object at said massive throw-in stage and furthermeasuring a flow rate (q) of the bulk material poured from the storageportion at said small throw-in stage, and further determining a timingin which the filling amount (W) of the bulk material filled in thefilling object at said small throw-in stage reaches W=W₀ -Wh to be aclosing timing of the opening/closing device.
 6. An apparatus forfilling bulk material according to claim 5, wherein a fall time of thebulk material for use in calculation of said falling amount is anaverage of fall times measured in a just nearby N cycle fillingoperation.